Advanced search formatting

I’m using the OneSocial theme, and the advanced search formatting is not working well. The calendar does not show month / year. Also, you have to click on the field label instead of the arrows to the right in order to see the options. You can see it here: https://www.brasileirosnosestadosunidos.com/eventos-2/

Any suggestions on how to fix this?

Thanks,

https://wordpress.org/plugins/events-manager/